EXPOSURE CONTROLLING MEANS FOR A VARIABLE FOCUS TYPE CAMERA

摘要

The invention relates to exposure controllers for cameras equipped with variable focal length lenses. The effective aperture of a lens varies with its focal length, so in a camera using such a lens where the correct exposure is determined from a look-up table giving the relationship between the shutter speed, photometered light value and film speed a different table is needed for each focal length of lens. The exposure controller of the invention uses only one look-up table and compensates for the varying focal length of the lens by shifting the photometered-light value or film speed value, used to determine the exposure, by an amount corresponding to the variation in open aperture value of the lens.